Colored photographic multilayer material



ct. 29, 1940. Y B, GASPAR 2,219,304

' COLORED PHOTOGRAPHIC MULTILAYER MATERIAL Filed Dee. s. lss

41.50 ca/wA/Ns 4 PRO funs-R am Snventor Para, W-

Cttorneg Patented Oct. 29, 1940 COLORED PHoToGRArmc MULTmAYR MATE RIAL

-Bla Gaspar, Hollywood, Calif.

Application December s, 193s, serial No. 243,887 In Great Britain December 9;, 1937 4 Claims.

Light-sensitive multilayer' `materials are known, which are formed by superimposed silver halide layers colored in the three colors, yellow magenta, and blue-green lfor subtractive color 5 photography in which material the yellow layer is sensitised to blue, the magenta layer to green, and the blue-'green layer to red. 'I'he use of such a material has, however, certain disadvantages. If, for instance, the coloration of the layers is 0 very intense, the actiniclight is prevented from entering the layers and the silver image will not extend to the bottom ofthe layers. Ifthereafter the dyestuff is destroyed at the points of Athe silver deposit, the lower strata of the layers l5 cannot be decolorised and pure white cannot be obtained.

In my U. S. Patent No. 1,985,344 dated December 25, 1934, I have pointed out that by sensitizing, for example, a yellow colored emulsion above, but to redorgreen light or to that part 'of blue light which is not absorbed by the dyestuff in the layer, the requirement of intense coloration of the layers and the necessity of completely penetrating exposure can be satisfied. On the other hand, one might imagine that lthe coloration of the layers could be chosen weak enough, so lthat -the exposure of the layer throughout its entire depth is possible even with light absorbed by thedyestuff. Such small dyestuff concentrations are suitable for images on apapersupport but in this case prints in somewhat distorted colors are obtained. It has been found that in the case of paper prints on a ma- 3'5 terial having low dyestui concentration in layers sensitized to light absorbed by the color of the layer the defects of the prints are due to the fact that the light which .acts on the layer throughout its'depth cannot be prevented by the weak color of the layer from passing through the layer and entering the following layer. If this following layer is sensitive for the light, which should only act in the preceding layer, the part image extends over the two layers instead of being restricted to the first one, and the false colors of the print are the result. In order to avoid this inconvenience and in order to produce a light-sensitive material on a paper support which allows" the printing of copies on' paper from multicolor originals or part images, the sec- 'ond of two superposed layers is dyed not only with a dyestui of a color complementary to the light to which this second layer is to be exposed but in addition with -a dyestui of the same color 85 the image forming dyestui present in the rst not to blue light, as in the material described,

layer. The additional dyestul in the second layer, as distinguished from the image forming dyestuff in the upper layer is, however, removable by treating solutions which do not affect the image forming dyestuffs or which act'on the image forming dyestuff only in' a selective manner according to the exposure of the layer.

Eample.-On to a paper support there are coated in superposition, a blue-green dyed emulsion sensitized to red light or one containing .a panchromatic sensitizer; a magenta dyed orthochromatic emulsion or one containing a green sensitizer, and finally a yellow dyed blue-snsi-(- tive emulsion, as shown in the figure of the drawlng.

The yellow dyed emulsion is the top layer and 15 contains the dyestuif Xylenewalkgelb G (Schultz Farbstofftabellen, Leipzig 1932, '7th edition, volure 2, page 2,32) in the form of its calcium salt in a concentration of 0.45 g. per sq. in. Then 20 follows the magenta layer which contains 0.3 g. per sq. m. of the dyestuif Tuchechtbrillantrot 2B (a dyestuff supplied by the Gesellschaft fuer Chemische Industrie in Basle and similar to the dyestuiI PolarbrillantrotB described in Brunner, '25 Analyse der Azofabstoffe, Berlin 1929, page 113) in the form of its N-methyl-naphthoquinolinium salt, which may conveniently be` formed by the action of a. solution containing N-methyl-quinolinium-methyl-sulphonate on the dyestuff. 'Ihis 30 4layer is formed by'ian ordinary blue-sensitive vemulsion to which a green-sensitizer has been added. The same layer further contains about 1.5 g. of the dyestui 4.4'methenylbis[1(p-sulphophenyl)-3-methyl-pyrazolone-5l described in my application Ser. No. 240,860 filed November 16, 1938. This yellow dyestuff maybe fixed in the layer in the form of its triphenyl guanidine salt. Behind the green sensitized layer containing the magenta dyestuif and the auxiliary yellow dyestui a panchromatic or red sensitized emulsion dyed blue-green by 0.35 g. per sq. m. of the dyestui Pontamine Sky Blue 5BX (Schultz Farbstofftabellen 1931, 7th edition, vol. l, number 513) is arranged on the paper support of the 45 combined multi-layer material. The blue-green dyestuff may be `xed in the form of an insoluble salt, and this layer may further contain 1 g. per sq.`m. of the dyestuff obtained from 1-(p.sul phophenyl)-3-methyl-pyrazolone-5 andv -ani- 50 lino-acroleine-anil as described in Example 3 of my application Ser. No. 240,860'1ed November 16, 1938, or of the sulphonic acid derived from methenyl bis oxythionaphthene (Beilstein,

Handbuch der OrganischenChemie, 4th edi- 55' tion, 1934, supplement, volume XIX, page 713) or other decolorisable red dyestui. The sulphonic acid derivative of methenyl-bis-oxythionaphthene may be obtained by the sulphonation of this body with fuming sulphuric acid containing 20% sulphur trioxide.

In the specification the term rst" layer refers to that one of two superposed layers which is rst illuminated by light and the term second layer refers to the following layer. The terms include the top layer and the middle layer in a three layer material as well as the middle layer and, the rear layer. The image forming dyestuffs may be water soluble dyestufs of low diffusion which fastly dye the layer or insoluble salts of water, soluble dyestuls or even insoluble dyes, such as' insoluble oxyor amino-azodyestuffs. The material may be exposed behind colored or black and white positive part images or behind a multicolor master-positive of the additive or subtractive type. The auxiliary dyestuifs are decolorised after exposure of the three layer material preferably by a developer of alkaline reaction, and the image-,forming dyestuffs are locally destroyed after development of the silver images, for example, by an acid thiocarbamide solution or by a solution containing 5% hydrobromic acid. If

necessary the silver is afterwards removed from the dyestuff image thus obtained.

What is claimed is:

1. A multilayer light-sensitive material comprising a support, carrying a plurality of superposed silver halide emulsion layers sensitive to light of diierent colors, at least one of the layers being dyed by a dye which is fast to ordinary photographic treating solutions but capable of bering locally bleached in the presence of a metallic silver image and which absorbs light rays for which the layer is predominantly sensitized, the one ofsaid plurality of superposed light-sensi- -tive layers arranged next behind said fast dyed being dyed by a dye which'is fastto ordinary photographic treating solutionsbiit capable of being locally bleached in the presence of a metallic silver-image and which absorbs light rays for which the layer is predominantly sensitized,l the one of said plurality of superposed light-sensitive layers arranged next behind said fast dyedv layer being colored with `a lter dye which is of substantially the same color as said fast dye and is destroyable by a photographic developer which does not remove said fast dye.

3. A multilayer light-sensitive material comprising a support, carrying a plurality of superposed silver halide emulsion layers sensitive to light of complementary colors, eachof the layers being dyed by a dye which is fast to ordinary photographic treating solutions but capable of being locally bleached in the presence of a metallic silver image and which. absorbs light rays for which the layer is predominantly sensitized, one of said plurality of superposed light-sensitive layers arranged next behind another of said layers being colored with a filter dye which is substantially of the same color as the fast dye in said other colored layer and is destroyable by an alka line photographic developer which does' not remove the fast dye in any of said layers.

4. A multilayer light-sensitive material cornprising a support, carrying a plurality of superposed silver halide emulslon layers sensitive to light of diierent colors, at least one of the layers being dyed by a dye which is fast to ordinary photographic treating solutions but capable of being locally bleached in the presence of a metallic silver image and which absorbs light rays for which the layer is predominantly sensitized, the

vone of said plurality of superposed light-sensitive layers arranged next behind said fast dyed .layer being colored with a removable filter dye of substantially the same color as the fast dye in said first mentioned layer and a dye which is fast to ordinary photographic treating solutions but 

